The present invention relates generally to chutes or slides. More specifically, the present invention relates to a selectively extensible chute assembly which is deployable from a vehicle for unloading the vehicle.
Previously, the bulk unloading of some objects from vehicles has been difficult. Such objects could withstand normal piling, stacking and routine jostling during transit in a vehicle but could not withstand a straight four-foot drop from a vehicle bed to the ground during the unloadiing process. Examples of such objects include semi-finished light metal objects, aluminum piston blanks for example, some plastic items, packaged fragile goods and fruits such as melons.
Some objects were unloaded by attaching a ramp to a rear end of a vehicle such as a trailer and sliding or rolling the objects down the ramp. Fragile objects, for example melons would, however, have been often damaged while being so unloaded. Rolling a melon down a standard ramp would have damaged the melon since the ramps are hard and the melons are easily bruised. Also, it is time consuming to assemble a ramp and attach it to the back of a vehicle when unloading is desired and detach and disassemble the ramp when a further movement of the veicle is desired. It is, moreover, frequently difficult to store even a collapsed ramp so that it is readily available for further use with the vehicle.
A rigid coal chute that is permanently attached to a tiltable trailer for unloading the trailer has been previously proposed. An example of such a chute is disclosed in U.S. Pat. No. 2,439,961 issued to Bauders on Apr. 20, 1948. The chute includes a plurality of telescopic tubular sections which are arranged to permit the chute to be extended and retracted. Rotatably mounted to a rear portion of the trailer is an elbow section to which an end tubular section is secured. The other tubular sections telescope over the end tubular section when the chute is in its retracted position. A plurality of bolts is used to secure the chute sections in their extended positions.
As an example of flexible unloading devices, inflatable evacuation slides for airplanes have been used previously. One evacuation slide is mounted in a folded condition on the interior of an aircraft door. Once the door is open, an ejector bag will be inflated which in turn will inflate lateral fabrication webs restraining the bag in a generally rectangular form thereby pushing the folded slide out of a container. The evacuation slide is then inflated to extend the slide to a ground surface thereby enabling passengers to reach the ground surface on the slide. Such an evacuation slide is disclosed in U.S. Pat. No. 3,910,532 issued to Fischer on Oct. 7, 1975. Other such airplane evacuation chutes are disclosed in U.S. Pat. Nos. 2,765,131; 3,595,357 and 4,013,247.
It has also been proposed to use an inflatable chute to convey fruit from an orchard to a fruit container. Such a chute is disclosed in U.S. Pat. No. 4,256,212 issued to Markano on Mar. 17, 1981. This chute has a set of longitudinally extending bottom tubes and a pair of lateral tubular walls all of which are inflatable to form a U-shaped channel which rests on the ground. In a deflated or flat condition, the chute can be retracted into a roll by a reel.
These prior unloading devices and chutes have various disadvantages. To overcome these disadvantages, it is an object of this invention to provide an unloading device for a tilting truck body that is not only selectively extendable, but is also retractable. It is also an object of this invention to provide an unloading device that is conveniently stored on the vehicle when not in use. A further object of this invention is to provide an unloading device that may be installed on trucks or trailers without requiring extensive alterations or modifications to the truck or trailer.
Accordingly, the unloading device of this invention includes a chute which incorporates a plurality of flexible tubular members that extend upon being inflated. The chute is attached to the rear of the truck or trailer body, so that when it is inflated, the chute extends from the floor of the body to the ground. The tubular members are continuously urged toward a retracted position by coil springs that extend longitudinally of the members. Air for inflating and extending the chute is provided by the existing air brake system on the truck or trailer. The air pressure in the members is sufficient to overcome the retracting force of the coil springs, thereby keeping the chute assembly extended until the air pressure is reduced.